the theme of alchemy, Eric Orr has used natural light as well as blood and fire in his environments that produce extreme retinal responses. Mary Corse's large white-on-white glass canvases have glass micro-beads embedded in the acrylic paint to create a surface that shifts dramatically with the light. Helen Pashgian created acrylic spheres, globes with an unreal glow, seemingly lighted from within. More recently, Gisela Colon, who has been recognized in ArtForum as a next generation light and space artist, has created "irregularly shaped wall mounted acrylic orbs... scarab-like objects achieve their iridescence via the play of natural light, yet the sculptures appear to change color as one moves around them, as if lit by multihued bulbs." McCracken states the following. "I was always primarily interested in form alone, but then to make a form, you have to make it out of something. So color seemed a natural material to use, because color is abstract. If you make a form that appears to be composed of color, then you have something, an object, that's pretty abstract. Just form alone would be more abstract, of course, because it's just a mental idea, but you don't have anything there for your perceptions to grapple with unless you make it out of a material. However, if you make it out of metal, or stone, or wood, or whatever, then you have something that to my mind may overemphasize the physical aspect and therefore be difficult to perceive as purely mental. An important thought behind this is that all things are essentially mental - that matter, while quite real on the one hand, is on the other hand composed of energy, and in turn, of pure thought." Exhibitions Light and Space art from California was shown at Germano Celant's influential exhibition of environment-based art at the 1976 Venice Biennale, "Ambiente/arte dal futurismo alla body art". The movement has rarely been shown together, as Wheeler rejected to be included in major museum exhibitions, because of his doubts that the works would be shown in the way they were intended, and Nordman refuses to be in group shows on Light and Space. In 2010, David Zwirner Gallery, New York presented an historic exhibition titled “Primary Atmospheres,” a term coined by art critic Dave Hickey to describe the contributions of Southern California artists to the Light & Space movement. As part of a series of exhibitions during